New, Efficient, and High-Yielding Asymmetric Synthesis of (4<i>S</i>,5<i>S</i>)-Cytoxazone
作者:Kollapudi Chandra Babu、Rapolu Naveen Reddy、Salluri Yellamanda Rao、Palnati Venkateshwarlu、Gutta Madhusudhan
DOI:10.1080/00397911.2011.563450
日期:2012.9
Abstract A new approach for the asymmetric synthesis of (4S,5S)-cytoxazone 1 in five steps and in 48% overall yield starting from commercially available (R)-epichlorohydrin has been described. The key step include stereoselective 1,2-addition of p-methoxyphenyl magnesium bromide (p-OMePhMgBr) to chiral N-sulfinimine derived from (R)-glyceraldehyde acetonide and (S)-t-BSA, which gave corresponding sulfinamide
摘要 描述了一种从市售 (R)-表氯醇开始,分五步不对称合成 (4S,5S)-胞嘧啶 1 的新方法,总产率为 48%。关键步骤包括对甲氧基苯基溴化镁 (p-OMePhMgBr) 的立体选择性 1,2-加成与衍生自 (R)-甘油醛丙酮化物和 (S)-t-BSA 的手性 N-亚磺亚胺,得到相应的亚磺酰胺 2非对映选择性。在一个步骤中对叔丁基磺酰基和 1,3-二甲基缩醛脱保护,然后进行 N-Boc 保护和随后的羰基化产生目标 (4S,5S)-胞嘧啶 1。图形摘要